Method of manufacturing semiconductor device

1. A method of manufacturing a semiconductor device, comprising: forming a first film on a semiconductor substrate and forming a second film on the first film formed; processing the formed second film to a first pattern including a plurality of linear parts and end portions formed in an end of each of the linear parts, having a width wider than the linear parts, forming a second pattern including a first opening that traverses the end portions of the first pattern on the second film; etching the second film of the second pattern, exposed in the first opening, so as to divide the end portion into an end portion close to the linear part and an end portion apart from the linear part; forming a third film so as to cover the first film and the second film after the end portion is divided, and etching back the third film so as to form a first side wall formed of the third film on side surfaces of the second film; forming a fourth film so as to cover the first to third films, and etching back the fourth film so as to form a second side wall formed of the fourth film on side surfaces of the first side wall so as to form a closed loop pattern sequentially formed around the divided end portion; and dividing the closed loop pattern, or a closed loop pattern formed in the first film by using the second side wall as a mask.

2. The method of manufacturing a semiconductor device according to claim 1 , further comprising: before the closed loop pattern is divided, removing the first side wall in whose side surface the second side wall is formed, and leaving the second film and the second side wall that are used as a mask for patterning the first film on the first film.

3. The method of manufacturing a semiconductor device according to claim 2 , wherein the first pattern is formed by that the formed second film is processed to a pattern including a plurality of line patterns of nearly L-shape formed of a linear part and an end portion having a width wider than the linear part, and then a slimming is carried out to the pattern.

4. The method of manufacturing a semiconductor device according to claim 3 , wherein the first pattern is formed by that the pattern is formed so that a ratio of a line width to a space width of the plurality of linear parts becomes almost 1:1, and the slimming is carried out to the pattern until the line width of each linear part becomes almost ⅓.

5. The method of manufacturing a semiconductor device according to claim 3 , wherein the dividing the end portion includes that an upper layer film is formed on the second pattern and in the first opening and the first opening is processed so as to have a narrower width, and then the second film exposed is etched.

6. The method of manufacturing a semiconductor device according to claim 3 , wherein the first opening is formed so as to have an opening width not more than four times of a line width of the linear part of the first pattern after the slimming is carried out.

7. The method of manufacturing a semiconductor device according to claim 3 , wherein the first side wall formed of the third film and the second side wall formed of the fourth film are formed so that the third and fourth films have film thickness substantively equal to a line width of the linear part of the first pattern after the slimming is carried out.

8. The method of manufacturing a semiconductor device according to claim 2 , wherein the dividing the end portion includes that an upper layer film is formed on the second pattern and in the first opening and the first opening is processed so as to have a narrower width, and then the second film exposed is etched.

9. The method of manufacturing a semiconductor device according to claim 1 , wherein the first pattern is formed by that the formed second film is processed to a pattern including a plurality of line patterns of nearly L-shape formed of a linear part and end portions having a width wider than the linear parts, and then a slimming is carried out to the pattern.

10. The method of manufacturing a semiconductor device according to claim 9 , wherein the first pattern is formed by that the pattern is formed so that a ratio of a line width to a space width of the plurality of linear parts becomes almost 1:1, and the slimming is carried out to the pattern until the line width of each linear part becomes almost ⅓.

11. The method of manufacturing a semiconductor device according to claim 10 , wherein the dividing the end portion includes that an upper layer film is formed on the second pattern and in the first opening and the first opening is processed so as to have a narrower width, and then the second film exposed is etched.

12. The method of manufacturing a semiconductor device according to claim 10 , wherein the first opening is formed so as to have an opening width not more than four times of a line width of the linear part of the first pattern after the slimming is carried out.

13. The method of manufacturing a semiconductor device according to claim 10 , wherein the first side wall formed of the third film and the second side wall formed of the fourth film are formed so that the third and fourth films have film thickness substantively equal to a line width of the linear part of the first pattern after the slimming is carried out.

14. The method of manufacturing a semiconductor device according to claim 9 , wherein the dividing the end portion includes that an upper layer film is formed on the second pattern and in the first opening and the first opening is processed so as to have a narrower width, and then the second film exposed is etched.

15. The method of manufacturing a semiconductor device according to claim 9 , wherein the first opening is formed so as to have an opening width not more than four times of a line width of the linear part of the first pattern after the slimming is carried out.

16. The method of manufacturing a semiconductor device according to claim 9 , wherein the first side wall formed of the third film and the second side wall formed of the fourth film are formed so that the third and fourth films have film thickness substantively equal to a line width of the linear part of the first pattern after the slimming is carried out.

17. The method of manufacturing a semiconductor device according to claim 1 , wherein the dividing the end portion includes that an upper layer film is formed on the second pattern and in the first opening and the first opening is processed so as to have a narrower width, and then the second film exposed is etched.

18. The method of manufacturing a semiconductor device according to claim 1 , wherein in forming the second pattern having the first opening, the first opening is formed at a location in which a distance from the first opening after the opening width thereof is thinned by a shrink method to the linear part of the first pattern after the slimming is carried out becomes not less than two times of the line width of the linear part of the first pattern after the slimming is carried out.

19. The method of manufacturing a semiconductor device according to claim 1 , further comprising: dividing the end portion in an almost perpendicular direction to a longitudinal direction of the linear part.

20. The method of manufacturing a semiconductor device according to claim 1 , further comprising: dividing the end portion in an almost parallel direction to a longitudinal direction of the linear part.